test.lox

object Testitem:<T> {
    method add(any t) -> void {
        if(!(t is T)) {
            throw("bad type");
        }
        else{
            System::println("good type");
        }
    }
}

object Test {

}

obj Testitem item = new Testitem:<System>();
item.add(new System());
item.add(10);